Predicting Transition in Turbomachinery—Part I: A Review and New Model Development

[+] Author and Article Information
T. J. Praisner

 Turbine Aerodynamics, United Technologies Pratt & Whitney, 400 Main St., M/S 169-29, East Hartford, CT 06108

J. P. Clark

Turbine Branch, Turbine Engine Division, Propulsion Directorate, Air Force Research Laboratory, Building 18, Room 136D, 1950 5th St., WPAFB, OH 45433john.clark3@wpafb.af.mil

J. Turbomach 129(1), 1-13 (Mar 01, 2004) (13 pages) doi:10.1115/1.2366513 History: Received October 01, 2003; Revised March 01, 2004

Here we report on an effort to include an empirically based transition modeling capability in a Reynolds Averaged Navier-Stokes solver. Well known empirical models for both attached- and separated-flow transition were tested against cascade data and found unsuitable for use in turbomachinery design. Consequently, a program was launched to develop models with sufficient accuracy for use in design. As a first step, accurate prediction of free stream turbulence development was identified as a prerequisite for accurate modeling. Additionally, a demonstrated capability to capture the effects of free stream turbulence on pre-transitional boundary layers became an impetus for the work. A computational fluid dynamics (CFD)-supplemented database of 104 experimental cascade cases was constructed to explore the development of new correlations. Dimensional analyses were performed to guide the work, and appropriate non-dimensional parameters were then extracted from CFD predictions of the laminar boundary layers existing on the airfoil surfaces prior to either transition onset or incipient separation. For attached-flow transition, onset was found to occur at a critical ratio of the boundary-layer diffusion time to a time scale associated with the energy-bearing turbulent eddies. In the case of separated-flow transition, it was found that the length of a separation bubble prior to turbulent reattachment was a simple function of the local momentum thickness at separation and the overall surface length traversed by a fluid element prior to separation. Both the attached- and separated-flow transition models were implemented into the design system as point-like trips.

Copyright © 2007 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.



Grahic Jump Location
Figure 9

A comparison of the efficacy of the current transition-onset model for attached flow with that of Abu-Ghannam and Shaw (11)

Grahic Jump Location
Figure 10

The current model for the onset of attached-flow transition compared to the database

Grahic Jump Location
Figure 11

Schematic representation of suction-side, laminar-separation characteristics showing both reattached (a) and stalled (b) conditions

Grahic Jump Location
Figure 1

Measured and predicted distributions of free stream turbulence around the C3X airfoil. Data are from Ames (8).

Grahic Jump Location
Figure 2

Comparison of measured and predicted turbulence dissipation around the C3X airfoil. Data are from Ames (8).

Grahic Jump Location
Figure 3

Measured convective heat transfer coefficient distributions from Arts (22) and CFD predictions run with fully laminar boundary layers

Grahic Jump Location
Figure 4

Results from CFD simulations run with the QL model for capturing pre-transitional quasi-laminar boundary layers

Grahic Jump Location
Figure 5

Non-dimensional momentum and thermal boundary layer profiles in a quasi-laminar boundary layer just prior to transition. Data are from Blair (25).

Grahic Jump Location
Figure 6

A comparison between the “universal” curve of Narasimha (43) and both experimental data and simulations from Clark (49)

Grahic Jump Location
Figure 7

A comparison between the current database for attached-flow transition onset and the correlation of Mayle (1)

Grahic Jump Location
Figure 8

A comparison between the transition onset criteria of Liepmann (54), Sharma (48), and Mayle and Schulz (57) and the current attached-flow database

Grahic Jump Location
Figure 12

Measured and predicted separation and reattachment locations. Transition was specified in the simulations based on data.

Grahic Jump Location
Figure 13

A comparison between the separated-flow transition model of Roberts (71) and the separated-flow transition database

Grahic Jump Location
Figure 14

A comparison between the separated-flow transition models of Mayle (1) and the separated-flow transition database

Grahic Jump Location
Figure 15

The current model and database for separated-flow transition. The model with a conservative shift is also shown.





Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In